1. Field of Disclosure
The present disclosure of invention relates to pixel array structures and display apparatuses including the same, and more particularly, to pixel array structures that provide for user perception of high image resolution while at the same time allowing for increased mass production yield and longer device lifespan.
2. Description of Related Technology
With the recent rapid development of semiconductor technologies, the typical screen size of flat panel display apparatuses has tended to increase while a desire remains that weight of the apparatus should decrease. Also, demand for flat panel display apparatuses with such superior properties has explosively increased.
Examples of such flat or otherwise thin panel display apparatuses include liquid crystal displays (LCDs), plasma display devices (PDPs), field emission display devices (FEDs), electroluminescence display devices (ELDs), electrophoresis display devices (EPDs), and an organic light-emitting display apparatuses.
In such display apparatuses, a plurality of unit pixels is formed by use of primary colored subpixels such as red subpixels, green subpixels, and blue subpixels. A variety of color images may be displayed through use of the cell like or unit pixels having the repeated pattern of primary colored subpixels. More specifically, the red subpixels, green subpixels, and the blue subpixels of the repeat cell may be arranged in wide variety of ways. The conventional approach had been to rely on striped vertical patterns wherein the red subpixels, green subpixels, and blue subpixels are each respectively arranged in a stripe form, that is, so that a plurality of subpixels of a same color are arranged as vertical columns to thereby yield respective red-only columns, green-only columns and blue-only columns.
In addition to including the light emitting subpixels, it is desirable to separate the subpixels from one another with a black matrix or alike blocking layer. However, in the display apparatuses that have the vertical stripe-type pixel array structures, one of the techniques used to increase a resolution thereof is to provide more blocking layers between the subpixels. Unfortunately, this results in a decrease of a light emission aperture ratio of the device. Since a minimum interval for forming an opening of a subpixel is predefined, it is difficult to manufacture a high-resolution organic light-emitting display (OLEO) apparatus having a stripe-type pixel array structure.
In this regard, a variety of so-called, pentile matrix structures have been proposed, in which a red subpixel and a blue subpixel are alternately formed in a same first column and two green subpixels are formed in an adjacent column. In such a pentile matrix structure, the number of independently driven green subpixels is double that of the red subpixels and the blue subpixels and the total number of subpixels per repeat group (unit cell) is four. In other words, the density of the red subpixels and of the blue subpixels is reduced by about ½ as compared with the older stripe-type pixel array structure wherein for each green subpixel there is one blue subpixel and one red subpixel. Hence, the total number of subpixels needed for producing a color image is reduced by about 2/6ths (due to having deleted 1 blue subpixel and 1 red subpixel for every pair of conventional RGB pixels) as compared with the stripe-type pixel array structure. As a result, this form of pentile matrix structure may ensure a high aperture ratio and achieve a substantially same cognitive (user-perceived) resolution as the stripe-type pixel array structure by using a so-called, subpixel rendering (SPR) driving method. (The described “pentile” matrix structure is one of alternate and so-named matrices. In another pentile matrix, there are 5 subpixels per repeat group, namely, one central blue subpixel and a checkerboard pattern formed around it by 2 red subpixels and 2 green subpixels.)
With regard to the above-described 2G/1B/1R pentile matrix structure, it is difficult to use it for implementing a high resolution greater than 440 subpixels per inch (ppi), and the reduction in the number of subpixels per repeat group may degrade an image quality during actual image reproduction.
It is to be understood that this background of the technology section is intended to provide useful background for understanding the here disclosed technology and as such, the technology background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to corresponding invention dates of subject matter disclosed herein.